In metallurgical laboratories the polishing of metal samples by hand for microscopic examination was similar but with emphasis on ensuring that when moving to the next finer grade of emery / wet & dry, the sample was turned 90 degrees, to show uniform material removal, retaining a flat surface.

After, say, 800 or 1000 grade grit,  for final polishing to an optically scratch-free surface we used "Selvit" (**) cloth as a carrier for  "Brasso" or "Silvo" for non-ferrous materials, or a diamond paste for harder iron or steel.

In more recent years a Mechanical carrier was used to hold the samples being polished, relieving the lab. technician of considerable amount of tedium.

(**) "Selvit" cloth is similar to the material used by opticians for cleaning / polishing lenses, and small strips are often included in the spectacle case.

Don

It's a strange thing, but my father was a metallurgist.  He died long before I went to university, so your comment has made me realize that we had this much in common - grinding down and polishing surfaces.  I was told at the age of 12 that I would not be going into the family business (metal finishing) and eventually decided on geology.  My current modelling projects have taken me closer to my father's calling and as a result I am currently researching the history of Birmingham's Jewellery Quarter.

Back to thin sections - as a student we had to make our slices 30 microns thin and one addition circular motion could be one too many.  It was an art!  Meantime the lab technicians had their mechanical carriers.  But I think I may have been more efficient as I made over 700 in two years!

OK, back to the 14XX - the pickups have been wired up and everything works.  The circuit board has not been fixed in place as I need to check clearances when the body shell is completed.  So that is my next focus - finishing the body.